Related Articles

Ants and gnats contribute to crop loss, reduced plant health, the spread of disease and sanitation issues. In some cases, they bite and/or sting. A variety of methods can defeat ant and gnat infestations in indoor potted plants and outdoor plants. Knowing the kind of ant or gnat with which you are dealing provides important clues to the best method to get rid of the pest.

Ants

1

Identify the type of ant that infested your indoor plants or outdoor plants. Use a magnifying glass to see the ants better. Each ant has three segments: head, thorax and abdomen; the thorax is the middle segment, and the abdomen is the end segment. Count the nodes between an ant's abdomen and thorax. One node narrows the ant's identity to an Argentine ant (Linepithema humile), carpenter ant (Camponotus spp.), odorous house ant (Tapinoma sessile) or velvety tree ant (Liometopum occidentale). Two nodes indicates the ant is a pavement ant (Tetramorium caespitum), Pharaoh ant (Monomorium pharaonis), red imported fire ant (Solenopsis invicta), Southern fire ant (Solenopsis xyloni) or thief ant (Solenopsis molesta). Compare your ant's size, color and other characteristics to physical descriptions of ant species to identify your ant's species.

2

Select pest management strategies most effective against the ant species affecting your plants. "Different ant species have varying food preferences and nesting locations, and respond to management practices differently," according to a University of California Integrated Pest Management Online article. General ant-control strategies include cleaning ant trails with soapy water at the first sign of ants, discovering ants' entry points and covering them with caulk or petroleum jelly and practicing good sanitation, removing sugar, pet food and garbage spills immediately.

3

Prune branches that cross the gap between your home or other building, plants and the ground. Place sticky traps on tree, shrub and bush trunks, especially where ants may interfere with your attempts to get rid of honeydew-producing pests such as soft scales, mealybugs, whiteflies and aphids. Remove old stumps that host ant colonies. If you find the ants' outdoor nest, dust it with silica gel, diatomaceous earth or other desiccant. Keep your home's pipes and roof in good repair. Clean rain gutters, avoiding excess moisture buildup, which attracts some ants. Keep your home's attic and the area under your house well-ventilated and dry. Store firewood away from buildings and off the ground. Carpenter ants may colonize in wood that is on the ground.

4

Apply a toxic chemical control if necessary. Carpenter ant nests are vulnerable to insecticide containing permethrin, cyfluthrin, boric acid or disodium octaborate tetrahydrate. Ant stakes and traps include a poison that attracts ants; ants carry the poison to their nest, where they and other ants eat it. Stakes and traps can take several weeks to be entirely effective. Baits are the easiest way to control Argentine ants, according to University of California Integrated Pest Management Online. Set ant-infested indoor potted plants outside, and submerge them in an insecticidal soap solution for at least 20 minutes. Follow instructions on the insecticidal soap's label.

Gnats

1

Inspect one of your gnat invaders to determine whether it is a fungus gnat (Sciaridae Orfelia spp. and Sciaridae Bradysia spp.) or eye gnat (Hippelates spp. and Liohippelates spp.). Use a magnifying glass to see the gnat better. Resembling a mosquito, a fungus gnat is 1/16 to 1/2 inch long, has slender legs, light-gray or clear wings and a long, segmented antenna, and is gray to black or orange-yellow. The Bradysia species sports wings with a Y-shaped vein. An eye gnat's body is 1/16 to 1/8 inch long and shiny black or gray; the eye gnat has yellow or orange-brown legs and wings that lack colored spots or patterns and display fewer visible veins.

2

Determine where the highest concentration of gnats congregate. Check window ledges and light fixtures. Gnats tend to move toward light sources. An option is to contact a pest-control company about using a light trap to obtain an accurate reading of your gnat problem's source.

4

Release Steinernema nematodes, Hypoaspis predatory mites or predatory hunter flies (Coenosia spp.) into a fungus gnat-infested area. Those creatures prey on fungus gnat adults and larvae. Avoid using a broad-spectrum insecticide if you use this biological-control method because the insecticide will kill the beneficial insects along with the gnats.

5

Apply an insecticide designed for gnats or flying insects if cultural and biological controls do not solve the gnat problem. A chemicals is only a temporary solution against gnats if their source is not treated, according to a North Carolina Cooperative Extension website article. Using pyrethrin, spinosad or Bacillus thuringiensis variation israelensis works on adult fungus gnats when the chemical is applied to the soil of a fungus gnat-infested plant. Yellow sticky traps catch adult gnats. A trap filled with an egg and water mixture helps trap eye gnats.

Tips

Do not intermingle infested plants with clean plants. Intermingling can spread the infested plants' problem. If the infestation is severe, in some cases the best course of action may be to remove and destroy the plants.

Some locations advise residents to report a suspected infestation of red imported fire ants. For example, Californians should call 1-888-4FIREANT to report a suspected infestation to the California Department of Food and Agriculture at 1-888-4FIREANT. The department's personnel will inspect and treat the infestation for free or offer a treatment recommendation. A University of California Integrated Pest Management Online article states homeowners should not use their own methods to control red imported fire ants.

Warning

Keep all traps, baits and toxic chemicals out of the reach of young children and pets.

About the Author

Tamara Christine has written more than 900 articles for a variety of clients since 2010. She holds a Bachelor of Arts in applied linguistics and an elementary teaching license. Additionally, she completed a course in digital journalism in 2014. She has more than 10 years experience teaching and gardening.